Alpha is a borough in Warren County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 2,369, reflecting a decline of 113 (-4.6%) from the 2,482 counted in the 2000 Census, which had in turn declined by 48 (-1.9%) from the 2,530 counted in the 1990 Census.
Alpha was incorporated as a borough from portions of Pohatcong Township by an act of the New Jersey Legislature passed on June 26, 1911, and signed by Governor Woodrow Wilson, based on the results of a referendum held on May 31, 1911. The borough was named for the Alpha Cement Works.
The borough is one of the easternmost locations within the Lehigh Valley region of Pennsylvania and New Jersey.
Formally known as Vulcanite, Alpha was incorporated on June 26, 1911, but its history can be traced back to a much earlier date. At the time of the Great Blizzard of 1888, there were only seven houses in what is now the corporate limits of Alpha. The exact date on which the first house in Alpha is uncertain. One of the first homes in the community was a two-room log cabin constructed by the Pursel family beside an old Indian Trail on the former property of the Vulcanite Portland Cement Company, now New Brunswick Avenue.
Less than two years after incorporating, the community obtained a continuation of the street car line from Phillipsburg and electric street lights were installed.
According to the United States Census Bureau, the borough had a total area of 1.698 square miles (4.397 km2), including 1.672 square miles (4.329 km2) of land and 0.026 square miles (0.068 km2) of water (1.54%).
Unincorporated communities, localities and place names located partially or completely within the borough include Vulcanite.
The borough is completely surrounded by Pohatcong Township, making it part of 21 pairs of "doughnut towns" in the state, where one municipality entirely surrounds another.
The 2010 United States Census counted 2,369 people, 964 households, and 632.384 families in the borough. The population density was 1,417.2 per square mile (547.2/km2). There were 1,032 housing units at an average density of 617.4 per square mile (238.4/km2). The racial makeup was 93.12% (2,206) White, 2.41% (57) Black or African American, 0.00% (0) Native American, 1.52% (36) Asian, 0.00% (0) Pacific Islander, 1.18% (28) from other races, and 1.77% (42) from two or more races.